build.mill

package build
import mill._, pythonlib._

object foo extends PythonModule {

  def mainScript = Task.Source { "src/foo.py" }

  def pythonDeps = Seq("Jinja2==3.1.4")

  object test extends PythonTests with TestModule.Unittest

}

// This is a basic Mill build for a single `PythonModule`, with one
// dependency and a test suite using the `Unittest` Library.
//
// You can download the example project using the **download** link above,
// or browse the full sources via the **browse** link.
// Ensure you have a JVM installed; the `./mill` script manages all other dependencies.
// All examples, from simple hello-world projects on this page to advanced
// xref:pythonlib/web-examples.adoc[web build examples]
// are fully executable and tested in Mill’s CI workflows.
//
// The source code for this module lives in the `src/` folder.
// Output for this module (typeChecked files, resolved dependency lists, …​) lives in `out/`.
//
// ----
// build.mill
// foo/
//     src/
//         foo/foo.py
//     resources/
//         ...
//     test/
//         src/
//             foo/test.py
// out/foo/
//     run.json
//     run.dest/
//     ...
//     test/
//         run.json
//         run.dest/
//         ...
// ----
//
// This example project uses one dependency - https://pypi.org/project/Jinja2/[Jinja2]
// for HTML rendering and uses it to wrap a given input string in HTML templates with proper escaping.
//
// Typical usage of a `PythonModule` is shown below:

/** Usage

> ./mill resolve foo._ # List what tasks are available to run
foo.bundle
...
foo.console
...
foo.run
...
foo.test
...
foo.typeCheck

> ./mill inspect foo.typeCheck  # Show documentation and inputs of a task
...
foo.typeCheck(PythonModule...)
    Run a typechecker on this module.
Inputs:
    foo.pythonExe
    foo.transitivePythonPath
    foo.sources
...

> ./mill foo.typeCheck  # TypeCheck the Python Files and notify errors
Success: no issues found in 1 source file

> ./mill foo.run --text "Hello Mill"  # run the main method with arguments
<h1>Hello Mill</h1>

> ./mill foo.test
...
test_escaping (test.TestScript...) ... ok
test_simple (test.TestScript...) ... ok
...Ran 2 tests...
OK
...

> ./mill show foo.bundle # Creates Bundle for the python file
".../out/foo/bundle.dest/bundle.pex"

> out/foo/bundle.dest/bundle.pex --text "Hello Mill" # running the PEX binary outside of Mill
<h1>Hello Mill</h1>

> sed -i.bak 's/print(main())/print(maaain())/g' foo/src/foo.py

> ./mill foo.typeCheck # if we make a typo in a method name, mypy flags it
error: ...Name "maaain" is not defined...

*/

// The output of every Mill task is stored in the `out/` folder under a name corresponding to
// the task that created it. e.g. The `typeCheck` task puts its metadata output in `out/typeCheck.json`,
// and its output files in `out/typeCheck.dest`.
// You can also use `show` to make Mill print out the metadata output for a particular task.
//
// You can run mill `resolve __` to see a full list of the different tasks that are available,
// `mill resolve _` to see the tasks within foo, `mill inspect typeCheck` to inspect a task’s doc-comment
// documentation or what it depends on, or `mill show foo.typeCheck` to show the output of any task.
//
// The most common **tasks** that Mill can run are cached tasks, such as `typeCheck`, `test`, `bundle` and
// `run`. Cached tasks do not re-evaluate unless one of their inputs changes, whereas commands re-run every time.
// See the documentation for https://mill-build.org/mill/main-branch/fundamentals/tasks.html[Tasks]
// for details on the different task types.